The present invention relates to a magnetic film of a high saturation magnetic flux density, a fabrication method therefor, a thin film magnetic head utilizing the magnetic film, and a magnetic disk drive provided with the thin film magnetic head.
With increased recording density of magnetic disk drives, recording media has been increased in coercivity. As a magnetic core material for a write head, a material is required accordingly that shows a high saturation magnetic flux density (Bs) and a strong magnetic field enough to sufficiently write information in a medium with high coercivity.
Materials that exhibit a high saturation magnetic flux density (Bs) include CoNiFe (Bs>1.7 T) having a Bs higher than that of Ni45Fe55 (Bs:1.5 teslas (T)), which is adopted presently as a magnetic core material as described in Patent Documents 1, 2, 3, and 4. Patent Document 5 also discloses a process of forming a plated film having a high Bs by making use of, as a plating solution composition, a plating solution to which no saccharin sodium is added. Furthermore, in Patent Document 6, the use of a two-element (Co and Fe) leads to the attainment of making the Bs higher. See Patent Document 1: Japanese Patent Laid-open No. 6-89422; Patent Document 2: Japanese Patent Laid-open No. 8-241503; Patent Document 3: Japanese Patent Laid-open No. 6-346202; Patent Document 4: Japanese Patent Laid-open No. 7-3489; Patent Document 5: Japanese Patent No. 2821456; Patent Document 6: Japanese Patent Laid-open No. 2002-280217.
In the above-described prior art, however, even though a CoNiFe-based material as a material exhibiting a high saturation magnetic flux density (Bs) is produced by electroplating, a sufficiently high saturation magnetic flux density cannot be obtained yet.